What is a Monteggia Fracture?
An individual is said to have Monteggia Fracture when there is an injury to the proximal radioulnar joint or the PRUJ. This usually happens whenever there is a fracture of the ulna which forms a part of the forearm. Monteggia Fracture is quite rare and occurs in only 5% of all cases of a forearm fracture. Falling on the outstretched hand is the most common mechanism of injury that causes Monteggia Fracture. The fracture of the ulna can be quite apparent on radiographs when taken after the injury. However, the findings related to the radial head dislocation can be easily overlooked since they are not clearly visible on plain film radiographs.
Thus it is vital if an individual is suspected to have a Monteggia Fracture to take radiographs of the entire elbow and forearm for an accurate diagnosis. A timely diagnosis and treatment is essential as a delay in treatment of an injury like a Monteggia Fracture can cause permanent disability and functional limitations of the affected arm.
Even after a Monteggia Fracture is diagnosed, the biggest hurdle is to assess the extent of the damage caused by the injury. The olecranon, distal and midshaft all are equally involved in a Monteggia Fracture which further complicates the picture. Treatment of Monteggia Fracture can be both conservative as well as surgical depending on the extent of the injury and the type of fracture sustained.
What Causes Monteggia Fracture?
As stated, the primary cause for a Monteggia Fracture is a fall on the outstretched hands. This usually happens while playing contact sports like football or rugby. A direct blow to the forearm from being assaulted or hit by a heavy object also has the potential to cause Monteggia Fractures.
A motor cycle crash at a high speed may also cause an individual to suffer from this injury. This fracture is not so common and occurs in only 5% of people with forearm injuries.
What are the Symptoms of a Monteggia Fracture?
As is the case with all fractures, immediately after the injury, the affected arm will have swelling and inflammation. There will be severe pain and the individual will find it impossible to move the affected extremity. In case of an open fracture, the bones of the fracture will be visible through the wounds and some fracture fragments may also poke through the skin surface.
In cases of a closed fracture, there will be a visible deformity suggesting that the bone at that area is either dislocated or fractured. Some people also complain of numbness along the affected extremity. Any attempts at moving the elbow will cause severe pain.
How is Monteggia Fracture Diagnosed?
Immediately upon presentation to the emergency room after the injury, plain radiographs of the affected extremity will be taken. If a Monteggia Fracture is suspected then orthogonal views of the forearm will be taken. Additionally, views of the elbow and wrist joints will also be taken to assess for the severity of the injury. Separate views of the elbow will be taken to see whether the proximal radioulnar joint is affected which in cases of a Monteggia Fracture will be positive.
Additionally, the ulnohumeral articulation and radiocapitellar joint will also be assessed to look for any injury at that location. The fracture of the ulna will be quite clearly seen; however the radial head dislocation may not be entirely clear and the chances of it being overlooked are quite high. Based on the results of these radiographs a confirmative diagnosis of a Monteggia Fracture is made.
How is Monteggia Fracture Treated?
The first priority of the physician upon arrival of the patient to the emergency room will be to control the pain. This can be managed with pain medications or NSAIDs. In cases of an open fracture, all debris will be removed from the wound as early as possible to prevent contamination and chances of an infection developing. The patient may be given intravenous antibiotics. The wound will then be irrigated and dressed with a dry dressing.
Once radiographs confirm a fracture, a reduction will be attempted at the emergency room itself. If it is not successful then the patient will be admitted for an inpatient consultation and further treatment plan will be devised based on the extent of the injury. In case of children suffering a Monteggia Fracture, immediate reduction and splint application will have to be performed. This will have to be done under general anesthesia due to the pain. The reduction will be confirmed with repeat radiographs.
Conservative treatments in children with Monteggia Fracture are in majority of the cases successful because children are still skeletally immature and the fractures are generally stable. The healing time of children also is faster making conservative approach towards treatment of a Monteggia Fracture the first choice for physicians in cases of children. Full restoration of strength and function can be achieved with conservative treatments in children since the healing is faster. If there are any deformities present at the end of the period of immobilization that can be corrected with future surgeries at optimal time.
In adults, however, an open reduction internal fixation is required. This will depend on whether there are any contraindications for the surgery. Generally, patients with a compromised immune system like the elderly or people with diseases like HIV cannot undergo surgery until they are deemed fit by their physicians. A closed reduction of the radial head dislocation in Monteggia Fracture should be done on an emergent basis, generally within the first 10 hours after surgery.
If this is not successful then the patient may have to undergo surgery for open reduction of the Monteggia Fracture. If there is any further delay, it may cause significant articular damage and nerve injury which may make it difficult for the patient to regain all motion and strength of the arm back. In cases of an open fracture in adults, immediate surgery is done to stabilize the fracture with plates and screws and prevent onset of any infection due to external contamination.
Postsurgery, the patient will be placed in a splint for a period of at least 4-6 weeks till the time the fracture stabilizes and the wound is healed. The patient will then require a period of extensive physical therapy to regain lost motion and strength due to the fracture itself and the prolonged period of immobilization. Serial debridement is sometimes required in cases where the fracture is open and the wound gets severely contaminated with dust and other debris prior to proceeding with surgery.
In cases where the patient is in a state where he or she cannot tolerate the surgery then nonoperative means by casting will be employed to stabilize the fracture and surgery will be delayed until the patient is fit enough. Research is still ongoing to identify better management strategies for Monteggia Fractures for better long term prognosis.
In essence, an accurate diagnosis and correct treatment strategy should be employed to completely treat Monteggia Fracture since this fracture is quite rare and certain characteristic features may be overlooked or missed by the treating physician.
What is the Overall Prognosis of a Monteggia Fracture?
The prognosis of individuals with Monteggia Fracture is quite good with treatment. People who are treated conservatively may have pain or nerve dysfunction for quite some time even after treatment. There may also be visible deformity present which will have to be treated with surgery. In some cases, ulnohumeral dislocations have been observed in people with Monteggia Fracture which have impacted the prognosis of individuals with this injury.
With surgical treatments, however, the prognosis remains quite good with little to no complications other than those inherent with a surgical treatment like infection, injury to adjacent nerves or blood vessels, and bleeding. Complete restoration of the function is normally seen in people after physical therapy once treated for Monteggia Fracture.
In cases where Monteggia Fracture is misdiagnosed or is not treated on time, then complications may develop. There may be nerve dysfunctions causing motor and sensory impairments in the affected arm. The patient may find it difficult to move the arm and use it normally. The patient will also find it extremely difficult to grip and grasp objects due to the PRUJ dislocation as is seen with Monteggia Fractures.